The present invention relates to haymaking machines for the lateral windrowing of fodder, comprising at least two rotary rake heads which are driven in rotation in such manner as to turn in the same direction about substantially vertical axes, and each of which is provided with several tool-carrier arms which extend outwards and can oscillate about their longitudinal axes under the action of a control mechanism in such manner as to cause the working tools, over a partial zone of their trajectory, to pivot upwards and in the direction opposite to the direction of rotation of the rotary rake heads. The said rotary rake heads are interconnected by means of a support chassis disposed obliquely in relation to the direction of travel of the machine in such manner that the said rotary rake heads are staggered in relation to one another towards the rear. This chassis is itself connected by means of a connection beam to a hitch device permitting coupling of the machine to the three-point hoist device of a propelling tractor.
These machines comprising rotary rake heads equipped with controlled working tools permit carrying out windrowing work of better quality than the machines where the working tools are immobile over their whole trajectory. In fact on machines equipped with immobile working tools the fodder is projected laterally at high speed so that it may clear itself from the said working tools. When the fodder is dry this projection causes significant stripping of leaves, involving a loss of nutrient elements. On the other hand on machines with controlled tools the fodder is deposited gently by the working tools which advantageously disengage themselves from the said fodder by virtue of their pivoting.
On known machines of the kind to which the present invention relates, the connection between the support chassis of the rotary rake heads and the hitch device is rigid during operation. These machines possess especially the drawback that when one turns towards the right or the left, for example at the end of a field or in a curve, the support chassis places itself in a position in which it is substantially perpendicular to the direction of travel of the machine. In this case the rotary rake heads are no longer staggered in relation to one another and each forms its own windrow, which is not desirable since this renders collection of the windrows more difficult.
One of the purposes of the present invention is to produce a haymaking machine as described in the introduction which is not very burdensome and does not possess the above-mentioned drawbacks of the known machines.